2016-12-10T00:05:58ZLong-term coding of personal and universal associations underlying the memory web in the human brain.http://hdl.handle.net/2381/38892
Title: Long-term coding of personal and universal associations underlying the memory web in the human brain.
Authors: De Falco, Emanuela; Ison, Matias J.; Fried, I; Quian Quiroga, Rodrigo
Abstract: Neurons in the medial temporal lobe (MTL), a critical area for declarative memory, have been shown to change their tuning in associative learning tasks. Yet, it is unclear how durable these neuronal representations are and if they outlast the execution of the task. To address this issue, we studied the responses of MTL neurons in neurosurgical patients to known concepts (people and places). Using association scores provided by the patients and a web-based metric, here we show that whenever MTL neurons respond to more than one concept, these concepts are typically related. Furthermore, the degree of association between concepts could be successfully predicted based on the neurons' response patterns. These results provide evidence for a long-term involvement of MTL neurons in the representation of durable associations, a hallmark of human declarative memory.
Description: The data that support the findings of this study are available
from the corresponding author on reasonable request. Supplementary Information accompanies this paper at http://www.nature.com/naturecommunications2016-12-09T17:13:20ZClinical validity of the Me and My School questionnaire: a self-report mental health measure for children and adolescents.http://hdl.handle.net/2381/38891
Title: Clinical validity of the Me and My School questionnaire: a self-report mental health measure for children and adolescents.
Authors: Patalay, P.; Deighton, J.; Fonagy, P.; Vostanis, Panos; Wolpert, M.
Abstract: BACKGROUND: The Me and My School Questionnaire (M&MS) is a self-report measure for children aged eight years and above that measures emotional difficulties and behavioural difficulties, and has been previously validated in a community sample. The present study aimed to assess its clinical sensitivity to justify its utility as a screening tool in schools. METHODS: Data were collected from service-users (n = 91, 8-15 years) and accompanying parent/carer in outpatient mental health services in England. A matched community sample (N = 91) were used to assess the measure's ability to discriminate between low- and high-risk samples. RESULTS: Receiver operating curves (area under the curve, emotional difficulties = .79; behavioural difficulties = .78), mean comparisons (effect size, emotional difficulties d = 1.17, behavioural difficulties = 1.12) and proportions above clinical thresholds indicate that the measure satisfactorily discriminates between the samples. The scales have good internal reliability (emotional difficulties α = .84; behavioural difficulties α = .82) and cross-informant agreement with parent-reported symptoms is comparable to existing measures (r = .30). CONCLUSION: The findings of this study indicate that the M&MS sufficiently discriminates between high-risk (clinic) and low-risk (community) samples, has good internal reliability, compares favourably with existing self-report measures of mental health and has comparable levels of agreement between parent-report and self-report to other measures. Alongside existing validation of the M&MS, these findings justify the measures use as a self-report screening tool for mental health problems in community settings for children aged as young as 8 years.2016-12-09T16:47:30ZA low cost workload generation approach through the cloud for capacity planning in Service-Oriented Systemshttp://hdl.handle.net/2381/38890
Title: A low cost workload generation approach through the cloud for capacity planning in Service-Oriented Systems
Authors: Ferreira, C. H. G.; Estrella, J. C.; Nunes, L. H.; Reiff-Marganiec, Stephan; Batista, B. G.; Nakamura, L. H. V.; Leite, D.; Peixoto, M.; Libardi, R. M. D. O.
Abstract: This paper presents a cloud approach for low cost capacity
planning evaluations. To perform these evaluations we
have to specify and measure the workload on the target system
to discover issues and make the necessary adjustments.
However, due to high costs, these evaluations are usually
done using simulations, which does not consider stochastic
effects. We propose to use a tool named PEESOS, a generic
and flexible approach to apply real workloads and measure
used resources on these real systems. As a proof of concept,
our case study use a real ticket sales service to evaluate the
influence of scalability in the resource provisioning to show
how PEESOS can lower the cost of such real evaluations.
The results show the efficiency and savings that we can obtain
using PEESOS for large-scale capacity planning evaluations
before the real services are deployed. This approach
can avoid several problems that real services faces when they
launch.2016-12-09T16:15:42ZTowards a Distributed Runtime Monitor for ICS/SCADA Systemshttp://hdl.handle.net/2381/38889
Title: Towards a Distributed Runtime Monitor for ICS/SCADA Systems
Authors: Wain, Andrew; Reiff-Marganiec, Stephan; Janicke, H.; Jones, K.
Abstract: Industrial Control Systems (ICS) and SCADA (Supervisory Control and Data Acquisition) systems are
typically used in industries such as electricity generation and supply, gas supply, logistics, manufacturing
and hospitals and are considered critical national infrastructure. The evolution of these systems from
isolated environments into internet connected ones, in combination with their long service life and realtime
nature have raised severe security concerns in the event of a cyber-attack. In this paper, we review
the current literature surrounding the threats, vulnerabilities, exploits and existing approaches to securing
vulnerable SCADA systems. We then focus specifically on the development of a distributed online runtime
monitor to detect violations of safety properties. We conclude with suggestions for further research needed
to progress the state of the art in the area of distributed online runtime verification of SCADA systems.
Description: Licence checked at http://www.bcs.org/upload/pdf/ewic-licence.pdf2016-12-09T16:10:14ZTowards a Gamified Approach for Enhancing the VBE Preparedness for Establishing Virtual Collaborationshttp://hdl.handle.net/2381/38888
Title: Towards a Gamified Approach for Enhancing the VBE Preparedness for Establishing Virtual Collaborations
Authors: Rajper, N.; Reiff-Marganiec, Stephan; Nizamani, Q.
Abstract: Formation of collaborative settings (virtual organizations, collaborative network organizations, etcetera) is hindered by the lack of trust between unfamiliar but potential partners. Gamification is the application of game design principles to non- game environments. We claim that incorporating the concepts of gamification into Virtual Organisation Breeding Environments (VBEs) leads to building trust between VBE members, as well as motivating them to be proactive members of the VBEs that contribute towards the flourishing of VBEs. This paper explores a novel gamified approach, supported by a suitable methodology, to address the relatively neglected concept of ‘preparedness’ of VBEs.2016-12-09T16:00:00ZTowards a software framework for the autonomous internet of thingshttp://hdl.handle.net/2381/38887
Title: Towards a software framework for the autonomous internet of things
Authors: Hernandez, M. E. P.; Reiff-Marganiec, Stephan
Abstract: IoT promises a world where Smart Objects (SO) are able to autonomously communicate and work together to make the (human) user's life easier. Popular approaches for development of IoT applications take for granted that on-object resources are evenly constrained. As consequence, we observe a trend towards a data-feeder architecture in which "smart objects" are simple data gatherers and senders. Raw data is stored and processed in cloud platforms feeding Web applications and services. The autonomy of SOs is then compromised as they are not able to operate without these platforms. We propose a framework and architecture for the development of IoT applications where smart objects exhibit autonomy in regards to platforms and human users. We completed the successful evaluation of our proposal with the implementation of a prototype and the execution of a use case for physical resources provisioning.2016-12-09T15:48:55ZPEESOS-Cloud: a workload-aware architecture for performance evaluation in service-oriented systemshttp://hdl.handle.net/2381/38886
Title: PEESOS-Cloud: a workload-aware architecture for performance evaluation in service-oriented systems
Authors: Ferreira, C. H. G.; Nunes, L. H.; Pereira Jr., L. A.; Nakamura, L. H.; Estrella, J. C.; Reiff-Marganiec, Stephan
Abstract: It is a challenging task to ensure quality in service-oriented systems deployed in cloud computing owing to the dynamicity of its environment. Many approaches have been adopted to identify and evaluate bottlenecks and problems in performance. The most common scenario consists of distributed systems that use a workload capable of enabling clients to exploit the target system in different operational conditions. However, one requirement that tends to be overlooked is to determine how the workload is executed, as software and hardware faults can lead to its mischaracterization. In this paper, a number of problems in the workload generation have been identified and summarized. A new architecture, called PEESOS-Cloud, is proposed which allows these services to be evaluated as well as to improve the ability of the workload so that it conforms with its described characteristics. Experiments in a cloud environment were conducted to show how PEESOS-Cloud works and validate its capabilities. Our experiment also showed that the mischaracterization of the workload leads to poor results, whereas an workload-aware implementation leads to a better performance evaluation.2016-12-09T15:40:29ZIncreasing Energy Efficiency on Smartphones through Data forecashinghttp://hdl.handle.net/2381/38885
Title: Increasing Energy Efficiency on Smartphones through Data forecashing
Authors: Xu, J.; Yang, D.; Wang, J.; Guan, C.; Reiff-Marganiec, Stephan; Shen, H.
Abstract: Smartphones are widely used in daily life to access
services and various functions require continuous communication,
which leads to increased energy consumption. However,
the development of battery and related energy saving technology
can not meet the demand for energy consumption. Much
of current research work focuses on energy models caring
much about energy consumption of every single application.
In this paper, we propose a data forecasting-based strategy for
increasing energy efficiency on smartphones based on the predictability
of data to be accessed. To achieve this, a combination
of Collaborative filtering with the k-means algorithm categorize
users with similar user groups and speculate use increased for
the data users will access. With this model, we also adopt data
pre-storing model and dynamic updating model. The simulation
results illustrate that our approach is leading to energy saving.2016-12-09T15:34:13ZCloud Simulator: A Cost Model Simulator Module for Cloudsimhttp://hdl.handle.net/2381/38884
Title: Cloud Simulator: A Cost Model Simulator Module for Cloudsim
Authors: Alves, D. C.; Batista, B. G.; Macahdo, D. L.; Reiff-Marganiec, Stephan; Kuehne, B. T.
Abstract: The vast cloud computing environment holds out good prospects for researchers in the computing technology field. However, with several Cloud providers offering different pricing models, the evaluation and modeling of Cloud environments and applications are getting harder because there is a lack of tools for this task. We propose the CM Cloud Simulator to fill this gap since it provides a comprehensive and dynamic simulation of applications with various deployment configurations and incurs the cost it would require when implemented in a Cloud Provider, according to the cost model of any service provider. The CM Cloud Simulator also provides custom-built cost models through the XML file.
Description: Support information as well as the
CM Cloud Simulator code is available at
https://github.com/diegoca80/CloudModule.2016-12-09T15:25:27ZOptimized Composite Service Transactions through Execution Results Predictionhttp://hdl.handle.net/2381/38883
Title: Optimized Composite Service Transactions through Execution Results Prediction
Authors: Xu, J.; Li, Z.; Chi, H.; Wang, M.; Guan, C.; Reiff-Marganiec, Stephan; Shen, H.
Abstract: Abstract:
Traditional web services transaction processing mechanism handle exception by forward recovery and backward recovery. These compensation mechanisms often lead to waste of resources and time. In this paper, we propose a framework for predicting outcomes of service executions as part of service compositions which allows to choose service instances that are likely to lead to a successful result in the first instance and thus reduces the need for invoking costly recovery mechanisms. The framework makes use of watchdogs to maintain an awareness of service availability and a pre-coordinator which has oversight of the whole composite Web service and acts as a control center. An analysis of a scenario shows that we cannot only provide users with a more satisfactory result, but also can reduce the overhead costs of resources and waste.2016-12-09T15:16:56ZFinancialisation, ownership and employee interests under private equity at the AA, part twohttp://hdl.handle.net/2381/38882
Title: Financialisation, ownership and employee interests under private equity at the AA, part two
Authors: Clark, Ian
Abstract: This article examines a theoretically informed case study of the effects of financialisation at the workplace. It focuses in particular on trade union de-recognition and trade union recognition in the furtherance of ownership interests. The paper reports on the continued diffusion of investor-owner interests under the private equity business model which has recently witnessed the AA re-listed on the stock market. It addresses two research questions. One, how are investor-owner interests secured by trade union de-recognition and re-recognition? Two, how and why, as a de-recognised trade union, does the GMB continue to campaign for and represent GMB members in the AA when the IDU (the independent democratic union) has sole recognition at the firm?2016-12-09T14:45:54ZTowards an Off-the-cloud IoT data processing Architecture via a Smart Car Parking Examplehttp://hdl.handle.net/2381/38881
Title: Towards an Off-the-cloud IoT data processing Architecture via a Smart Car Parking Example
Authors: Alturki, Badraddin; Reiff-Marganiec, Stephan
Abstract: Nowadays, it is obvious that technology has revolutionised our
lives by supporting us to do complicated jobs. The Internet of
Things (IoT) is one of the emerging technologies. One of the most
significant current research topics in the IoT is smart city. The
smart city includes several applications such assmart home, smart
industry and smart mobility. The smart car parking system is an
aspect of smart mobility and an important application in smart
city projects, because of the rapidly increasing number of cars in
urban areas. However, most of the current proposals in smart car
parking systems manage the data on the cloud side which is a
problem since the system needs to send the raw data from sensor
to cloud and receive instructions back: this is expensive in terms
of energy and data transmission cost. To tackle this issue we
present a proposal to save energy and to reduce the amount of data
that is transmitted over the network to cloud by processing closer
to source in this paper. The architecture is demonstrated through
a case study.2016-12-09T14:38:33ZTHE 2011 OUTBURST OF RECURRENT NOVA T Pyx: X-RAY OBSERVATIONS EXPOSE THE WHITE DWARF MASS AND EJECTION DYNAMICShttp://hdl.handle.net/2381/38880
Title: THE 2011 OUTBURST OF RECURRENT NOVA T Pyx: X-RAY OBSERVATIONS EXPOSE THE WHITE DWARF MASS AND EJECTION DYNAMICS
Authors: Chomiuk, L.; Nelson, T.; Mukai, K.; Sokoloski, J. L.; Rupen, M. P.; Page, Kim L.; Osborne, Julian P.; Kuulkers, E.; Mioduszewski, A. J.; Roy, N.; Weston, J.; Krauss, M. I.
Abstract: The recurrent nova T Pyx underwent its sixth historical outburst in 2011, and became the subject of an intensive
multi-wavelength observational campaign. We analyze data from the Swift and Suzaku satellites to produce a detailed
X-ray light curve augmented by epochs of spectral information. X-ray observations yield mostly non-detections
in the first four months of outburst, but both a super-soft and hard X-ray component rise rapidly after Day 115.
The super-soft X-ray component, attributable to the photosphere of the nuclear-burning white dwarf, is relatively
cool (∼45 eV) and implies that the white dwarf in T Pyx is significantly below the Chandrasekhar mass (∼~1 M☉ ).
The late turn-on time of the super-soft component yields a large nova ejecta mass (~> 10^−5 M☉), consistent with
estimates at other wavelengths. The hard X-ray component is well fit by a ∼1 keV thermal plasma, and is attributed
to shocks internal to the 2011 nova ejecta. The presence of a strong oxygen line in this thermal plasma on Day 194
requires a significantly super-solar abundance of oxygen and implies that the ejecta are polluted by white dwarf
material. The X-ray light curve can be explained by a dual-phase ejection, with a significant delay between the first
and second ejection phases, and the second ejection finally released two months after outburst. A delayed ejection
is consistent with optical and radio observations of T Pyx, but the physical mechanism producing such a delay
remains a mystery.2016-12-09T14:31:38ZVascular changes in early TSH-induced thyroid tumours in the rat.http://hdl.handle.net/2381/38879
Title: Vascular changes in early TSH-induced thyroid tumours in the rat.
Authors: Wynford-Thomas, D.; Stringer, B. M.; Gomez Morales, M.; Williams, E. D.2016-12-09T12:05:55ZLaminin and fibronectin in rectal adenocarcinoma: Relationship to tumour grade, stage and metastasishttp://hdl.handle.net/2381/38878
Title: Laminin and fibronectin in rectal adenocarcinoma: Relationship to tumour grade, stage and metastasis
Authors: Forster, S. J.; Talbot, I. C .; Critchley, D. R.
Abstract: Using an immunoperoxidase procedure, we have examined the distribution of laminin and fibronectin in normal human large intestinal mucosa and in 50 cases of rectal adenocarcinoma for which extensive clinical follow up was available. In normal tissue, laminin staining was largely restricted to basement membranes, including that underlying the epithelial cells, whereas fibronectin was found in both basement membranes and surrounding connective tissue. In rectal carcinomas, basement membrane-like staining for laminin associated with tumour cells was found in only 27 out of the 50 cases studied. Statistical analysis showed that the presence of laminin-containing basement membranes was correlated with low histological grade (well-differentiated tumours), but not with stage (progression through the bowel wall and the development of lymph node metastases) and, in a highly significant way, with a reduced incidence of distant metastases and increased patient survival. Although fibronectin was found in tumour cell basement membranes where these were present, it was also found in the stroma of all 50 tumours. There was no apparent correlation between the presence of stromal fibronectin and grade, stage or development of metastases. Finally, attention is drawn to some of the technical difficulties in detecting basement membrane antigens in formalin-fixed tissue, the material most frequently available for retrospective study.2016-12-09T11:55:21ZLack of correlation between metastasis of human rectal carcinoma and the absence of stromal fibronectinhttp://hdl.handle.net/2381/38877
Title: Lack of correlation between metastasis of human rectal carcinoma and the absence of stromal fibronectin
Authors: Niemczuk, P.; Perkins, R. M.; Talbot, I. C.; Critchley, D. R.
Abstract: In a retrospective study we have used an immunoperoxidase procedure to localize the glycoprotein fibronectin in human rectal carcinomas, concentrating on tumour invading thick-walled extramural veins. Fibronectin was present in 29 out of 38 cases, in connective tissue stroma, and was not in direct association with the tumour cells, except in areas of necrosis. We found no correlation between the presence or absence of stromal fibronectin and (1) the degree of cellular differentiation within the tumour, (2) tumour progression (Dukes' classification) (3) the subsequent development of metastases and (4) patient longevity. OUr results do not support the conclusions from in vitro studies (Smith et al., 1979) that the metastatic potential of carcinomas may be partly determined by the ability of tumour cells to synthesize pericellular fibronectin.2016-12-09T11:51:00ZGeneral approach for the determination of the magneto-angular dependence of the critical current of YBCO coated conductorshttp://hdl.handle.net/2381/38876
Title: General approach for the determination of the magneto-angular dependence of the critical current of YBCO coated conductors
Authors: Zhang, X.; Zhong, Z.; Ruiz, H. S.; Geng, J.; Coombs, T. A.
Abstract: The physical understanding and numerical modelling of superconducting devices which exploit
the high performance of second generation high temperature superconducting tapes (2G-HTS), is
commonly hindered by the lack of accurate functions which allow the consideration of the in-field
dependence of the critical current. This is true regardless of the manufacturer of the superconducting
tape. In this paper, we present a general approach for determining a unified function Ic(B, θ),
ultimately capable of describing the magneto angular dependence of the in-field critical current of
commercial 2G-HTS tapes in the Lorentz configuration. Five widely different superconducting tapes,
provided by three different manufacturers, have been tested in a liquid nitrogen bath and external
magnetic fields of up to 400 mT. The critical current was recorded at 90 different orientations of the
magnetic field ranging from θ = 0◦
, i.e., with B aligned with the crystallographic ab-planes of the
YBCO layer, towards ±90◦
, i.e., with B perpendicular to the wider surfaces of the 2G-HTS tape.
The whole set of experimental data has been analysed using a novel multi-objective model capable
of predicting a sole function Ic(B, θ). This allows an accurate validation of the experimental data
regardless of the fabrication differences and widths of the superconducting tapes. It is shown that, in
spite of the wide set of differences between the fabrication and composition of the considered tapes,
at liquid nitrogen temperature the magneto-angular dependence of the in-field critical current of
YBCO-based 2G-HTS tapes, can be described by a universal function Ic(f(B), θ), with a power law
field dependence dominated by the Kim’s factor B/B0, and an angular dependence moderated by
the electron mass anisotropy ratio of the YBCO layer.2016-12-09T09:56:24ZMeasurements of the rotation rate of the jovian mid-to-low latitude ionospherehttp://hdl.handle.net/2381/38875
Title: Measurements of the rotation rate of the jovian mid-to-low latitude ionosphere
Authors: Johnson, Rosie E.; Stallard, Tom S.; Melin, Henrik; Miller, S.; Nichols, Jonathan D.
Abstract: Previous studies of Jupiter’s upper atmosphere often assume that the mid-to-low latitude ionosphere is
corotating, but a model describing an observed asymmetry in hydrogen Lyman-α emission (∼1000 km
above the 1 bar level) disagrees with this assumption. From measurements of the Doppler shifted
H+
3 ν2 Q(1, 0−) line at 3.953 μm using the IRTF, the line-of-sight velocities of the H+
3 ions were derived in
the planetary reference frame and found to be 0.091 ± 0.25 km s−1, 0.0082 ± 0.30 km s−1 and 0.31 ±
0.51 km s−1 in 1998, 2007 and 2013 respectively. These zero velocities represent corotation at the midto-low
latitude region of Jupiter’s ionosphere. There is no evidence of flows associated with the hydrogen
Lyman-α emission asymmetries detected in the peak H+
3 emission layer (∼550 km above the 1 bar level),
and we assert that the H+
3 ions in Jupiter’s mid-to-low latitude are rigidly corotating.2016-12-08T14:27:07ZOptimal Location and Minimum Number of Superconducting Fault Current Limiters for the Protection of Power Gridshttp://hdl.handle.net/2381/38874
Title: Optimal Location and Minimum Number of Superconducting Fault Current Limiters for the Protection of Power Grids
Authors: Zhang, X.; Geng, J.; Coombs, T. A.; Ruiz, H. S.
Abstract: This paper presents a novel method to determine the optimal strategy for the allocation of multiple resistive superconducting
fault current limiters (SFCLs) aiming to improve the overall protection of standard power grids. The
presented approach allows for the straightforward determination of the optimal resistance of the SFCL, accounting
for short circuit events occurring at different locations, by modelling the electro-thermal properties of the SFCL via a
temperature dependent E-J power law. This material law, based on previous experimental evidence, allows for the introduction
of flux pinning, flux creep, and flux flow properties of the superconducting material within a minimum level
of complexity. Thereby, we have observed a distinctive kink pattern in the current limiting profiles of the SFCLs, from
which no further reduction of the first peak of the fault current is achieved when a greater resistance is considered,
allowing a univocal determination of the optimum SFCL resistance. This peculiarity is not observed when the model
for the quench properties of the SFCL is simplified towards an exponential resistance, although the last can be used as
an auxiliary process for addressing the first guess on the resistance value required for a specific strategy, as it demands
less computing time. We have also determined that for many of the cases studied, i.e, for the combinations between
one or more SFCLs installed at different locations, and those subjected to fault events located at different points in
the network, the recovery time of the superconducting properties of at least one of the SFCLs can last for more than
five minutes, constraining the feasibility of a large-scale deployment of this technology. However, by assuming that
the practical operation of the SFCL is assisted by the automatic operation of a bypass switch when the SC material
is fully quenched, we have determined that the optimal strategy for the overall protection of power grids of standard
topology requires a maximum of three SFCLs, with recovery times of less than a few seconds. This information is of
remarkable value for power system operators, as it can establish a maximum investment threshold which ultimately
can facilitate making decisions regarding the deployment of SFCL technologies.
Description: This work was supported by the Engineering and
Physical Sciences Research Council (EPSRC) project
NMZF/064. X. Zhang acknowledges a grant from the
China Scholarship Council (No. 201408060080).2016-12-08T14:18:57ZFunctional adaptation underpinned the evolutionary assembly of the earliest vertebrate skeletonhttp://hdl.handle.net/2381/38873
Title: Functional adaptation underpinned the evolutionary assembly of the earliest vertebrate skeleton
Authors: Murdock, Duncan J. E.; Rayfield, E. J.; Donoghue, P. C. J.
Abstract: Conodonts are the first vertebrates to bear a mineralized skeleton, restricted to an array of tooth-like feeding elements. The functional implications for the development of tooth-like elements differentiated into two tissues is tested using 2D finite element modeling, mapping the patterns of stress and strain that elements with differing material properties exhibited during function. Addition of a stiff crown does not change the patterns of stress, rather it reduces the deformation of the element under the same force regime, and distributes stress more evenly across the element. The euconodont crown, like vertebrate dental enamel, serves to stiffen the element and protect the underlying dentine. Stiffness of the crown may be a contributing factor to the subsequent diversity of euconodont form, and logically function, by allowing a greater range of feeding strategies to be employed. The euconodont crown also serves as an analogue to enamel and enameloid, demonstrating that enamel-like tissues have evolved multiple times in independent vertebrate lineages, likely as a response to similar selective pressures. Conodonts can, therefore, serve as an independent test on hypotheses of the effect of ecology on the development of the vertebrate skeleton.2016-12-08T11:57:44ZParent's information seeking in acute childhood illness: what helps and what hinders decision making?http://hdl.handle.net/2381/38872
Title: Parent's information seeking in acute childhood illness: what helps and what hinders decision making?
Authors: Neill, SJ; Jones, CH; Lakhanpaul, M; Roland, DT; Thompson, MJ; ASK SNIFF research team
Abstract: CONTEXT: Acute illness is a universal experience in early childhood. Parents find it difficult to determine whether or not their child requires medical care and seek information to inform their decision making. Little is known about parents' information seeking behaviour and what helps or hinders their decision making. OBJECTIVE: This study aimed to explore parents' use of information resources during decision making in acute childhood illness at home. DESIGN/METHOD: This exploratory qualitative study used focus groups and interviews to collect data from parents of children under 5 years of age. SETTING AND PARTICIPANTS: Twenty-seven parents were recruited in the East Midlands, UK, in South Asian and Gypsy/Travelling communities, a Children's Centre and a private sector day nursery. FINDINGS: Parents' pre-consultation information seeking was dominated by the internet, albeit with limited success. Parents liked easy to access, professionally validated and simple messages with access to more detailed information. Some parents always sought information through personal contact, whilst others did so when independent information seeking failed. When consulting a healthcare professional, parents liked to be given information to refer to later, although the information received varied. Importantly, neither hard copy nor the internet was accessible for parents with low levels of literacy. DISCUSSION AND CONCLUSIONS: Although there is a wealth of information parents can access independently, our findings indicate a need for easy access to clearly signposted, professionally validated resources and available in a range of formats provided through different delivery systems. One size does not fit all.2016-12-08T11:53:26ZThe technofossil record of humanshttp://hdl.handle.net/2381/38871
Title: The technofossil record of humans
Authors: Zalasiewicz, Jan; Williams, Mark; Waters, C. N.; Barnosky, A. D.; Haff, P.
Abstract: As humans have colonised and modified the Earth’s surface, they have developed progressively more sophisticated tools and technologies. These underpin a new kind of stratigraphy, that we term technostratigraphy, marked by the geologically accelerated evolution and diversification of technofossils – the preservable material remains of the technosphere (Haff, 2013), driven by human purpose and transmitted cultural memory, and with the dynamics of an emergent system. The technosphere, present in some form for most of the Quaternary, shows several thresholds. Its expansion and transcontinental synchronisation in the mid 20th century has produced a global technostratigraphy that combines very high time-resolution, great geometrical complexity and wide (including transplanetary) extent. Technostratigraphy can help characterise the deposits of a potential Anthropocene Epoch and its emergence marks a step change in planetary mode.2016-12-08T11:46:11ZValidating the ffowcs williams and hawkings acoustic analogy implementation in antareshttp://hdl.handle.net/2381/38870
Title: Validating the ffowcs williams and hawkings acoustic analogy implementation in antares
Authors: Di Stefano, Danilo; Rona, Aldo; Hallf, Edward; Morfey, Christopher L.; Puigt, Guillaume
Abstract: Progress is presented in the development of a Ffowcs Williams and Hawkings (FW-H) acoustic analogy post-processor for time-resolved Computational Fluid Dynamics (CFD) simulations. The tool is coded in Python and embedded in Antares, a post-treatment package (developed by Cerfacs, France) of wide access and usability for the scientific community. Tests on monopoles, dipoles, and quadrupoles show good predictions of pressure fluctuation and directivity against reference analytical results, validating the software for applications to stationary elementary sources. The proximity of these sources to a corner of the FW-H integration surface is shown to adversely affect the predictions and good agreement with the benchmark sound field is restored by an appropriate sizing and placement of the FW-H surface. Guidelines for obtaining predictions that are substantially independent of the size and placement of the FW-H surface are provided in terms of the spatial resolution of the discretised FW-H surface.2016-12-08T11:26:48ZOptimized prefactored compact schemes for wave propagation phenomenahttp://hdl.handle.net/2381/38869
Title: Optimized prefactored compact schemes for wave propagation phenomena
Authors: Rona, Aldo; Hall, Edward; Spisso, Ivan
Abstract: A new family of prefactored cost-optimized schemes is developed to minimize the computational cost for a given level of error in linear wave propagation applications, such as aerodynamic sound propagation. This work extends the theory of Pirozzoli1 to the pref-actored compact high-order schemes of Hixon,2 which are MacCormack type schemes that use discrete Padé approximations. An explicit multi-step Runge-Kutta scheme advances the states in time. Theoretical predictions for spatial and temporal error bounds are used to drive the optimization process. Theoretical comparisons of the cost-optimized schemes with a classical benchmark scheme are made. Then, two numerical experiments assess the computational efficiency of the cost-optimised schemes for computational aeroacoustic applications. A polychromatic sinusoidal test-case verifies that the cost-optimized schemes perform according to the design high-order accuracy characteristics for this class of problems. For this test case, upwards of a 50% computational cost-saving at the design level of error is recorded. The final test case shows that the cost-optimized schemes can give substantial cost savings for problems where a fully broadband signal needs to be resolved.2016-12-08T11:11:40ZOClO and BrO observations in the volcanic plume of Mt. Etna – implications on the chemistry of chlorine and bromine species in volcanic plumeshttp://hdl.handle.net/2381/38868
Title: OClO and BrO observations in the volcanic plume of Mt. Etna – implications on the chemistry of chlorine and bromine species in volcanic plumes
Authors: Gliß, J.; Bobrowski, N.; Vogel, L.; Pöhler, D.; Platt, U.
Abstract: Spatial and temporal profiles of chlorine dioxide (OClO), bromine monoxide (BrO) and sulfur dioxide (SO2) of the volcanic plume at Mt. Etna, Italy, were investigated in September 2012 using Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS). OClO was detected in 119 individual measurements covering plume ages up to 6 min. BrO could be detected in 452 spectra up to 23 min downwind. The retrieved slant column densities (SCDs) reached maximum values of 2.0 × 1014 molecules cm-2 (OClO) and 1.1 × 1015 molecules cm-2 (BrO).
Mean mixing ratios of BrO and OClO were estimated assuming a circular plume cross section. Furthermore, ClO mixing ratios were derived directly from the BrO and OClO-SCDs. Average abundances of BrO = 1.35 ppb, OClO = 300 ppt and ClO = 139 ppt were found in the young plume (plume age τ < 4 min) with peak values of 2.7 ppb (BrO), 600 ppt (OClO) and 235 ppt (ClO) respectively.
The chemical evolution of BrO and OClO in the plume was investigated in great detail by analysing the OClO/SO2 and BrO/SO2 ratios as a function of plume age τ. A marked increase of both ratios was observed in the young plume (τ < 142 s) and a levelling off at larger plume ages showing mean SO2 ratios of 3.17 × 10-5 (OClO/SO2) and 1.65 × 10-4 (BrO/SO2). OClO was less abundant in the plume compared to BrO with a mean OClO/BrO ratio of 0.16 at plume ages exceeding 3 min.
A measurement performed in the early morning at low solar radiances revealed BrO/SO2 and OClO/SO2 ratios increasing with time. This observation substantiates the importance of photochemistry regarding the formation of BrO and OClO in volcanic plumes.
These findings support the current understanding of the underlying chemistry, namely, that BrO is formed in an autocatalytic, heterogeneous reaction mechanism (in literature often referred to as "bromine explosion") and that OClO is formed in the reaction of OClO with BrO.
These new findings, especially the very detailed observation of the BrO and OClO formation in the young plume, were used to infer the prevailing Cl-atom concentrations in the plume. Relatively small values ranging from [Cl] = 2.5 × 106 cm-3 (assuming 80 ppb background O3) to [Cl] = 2.0 × 108 cm-3 (at 1 ppb O3) were calculated at plume ages of about 2 min. Based on these Cl abundances, a potential – chlorine-induced – depletion of tropospheric methane (CH4) in the plume was investigated. CH4 lifetimes between 14 h (at 1 ppb O3) and 47 days (at 80 ppb O3) were derived. While these lifetimes are considerably shorter than the atmospheric lifetime of CH4, the impact of gaseous chlorine on the CH4 budget in the plume environment should nevertheless be relatively small due to plume dispersion (decreasing Cl concentrations) and ongoing mixing of the plume with the surrounding atmosphere (replenishing O3 and CH4).
In addition, all spectra were analysed for signatures of IO, OIO and BrO. None of these species could be detected. Upper limits for IO/SO2, OIO/SO2 and OBrO/SO2 are 1.8 × 10-6, 2.0 × 10-5 and 1.1 × 10-5 respectively.2016-12-08T10:42:07ZCISAPS: Complex Informational Spectrum for the Analysis of Protein Sequenceshttp://hdl.handle.net/2381/38867
Title: CISAPS: Complex Informational Spectrum for the Analysis of Protein Sequences
Authors: Chrysostomou, Charalambos; Seker, H.; Aydin, N.
Abstract: Complex informational spectrum analysis for protein sequences (CISAPS) and its web-based server are developed and presented. As recent studies show, only the use of the absolute spectrum in the analysis of protein sequences using the informational spectrum analysis is proven to be insufficient. Therefore, CISAPS is developed to consider and provide results in three forms including absolute, real, and imaginary spectrum. Biologically related features to the analysis of influenza A subtypes as presented as a case study in this study can also appear individually either in the real or imaginary spectrum. As the results presented, protein classes can present similarities or differences according to the features extracted from CISAPS web server. These associations are probable to be related with the protein feature that the specific amino acid index represents. In addition, various technical issues such as zero-padding and windowing that may affect the analysis are also addressed. CISAPS uses an expanded list of 611 unique amino acid indices where each one represents a different property to perform the analysis. This web-based server enables researchers with little knowledge of signal processing methods to apply and include complex informational spectrum analysis to their work.2016-12-08T10:36:56ZPerceptual task induces saccadic adaptation by target selection.http://hdl.handle.net/2381/38866
Title: Perceptual task induces saccadic adaptation by target selection.
Authors: Schütz, A. C.; Souto, David
Abstract: Adaptation of saccades can be induced by different error signals, such as retinal position errors, prediction errors, or reinforcement learning. Recently, we showed that a shift in the spatial goal of a perceptual task can induce saccadic adaptation, in the absence of a bottom-up position error. Here, we investigated whether this top-down effect is mediated by the visibility of the task-relevant object, by reinforcement due to the feedback about the perceptual judgment or by a target selection mechanism. Participants were asked to discriminate visual stimuli arranged in a vertical compound. To induce adaptation, the discrimination target was presented at eccentric locations in the compound. In the first experiment, we compared adaptation with an easy and difficult discrimination. In the second experiment, we compared adaptation when feedback about the perceptual task was valid and when feedback was provided but was unrelated to performance. In the third experiment, we compared adaptation with instructions to fixate one of the elements in the compound-target selection-to the perceptual task condition-target selection and discrimination. To control for a bottom-up stimulus effect, we ran a fourth experiment in which the only instruction was to look at the compound. The saccade amplitude data were fitted by a two-state model distinguishing between an immediate and a gradual error correction process. We replicated our finding that a perceptual task can drive adaptation of saccades. Adaptation showed no effect of feedback reliability, nor an effect of the perceptual task beyond target selection. Adaptation was induced by a top-down signal since it was absent when there was no target selection instruction and no perceptual task. The immediate error correction was larger for the difficult than for the easy condition, suggesting that task difficulty affects mainly voluntary saccade targeting. In addition, the repetition of experiments one week later increased the magnitude of the gradual error correction. The results dissociate two distinct components of adaptation: an immediate and a gradual error correction. We conclude that perceptual-task induced adaptation is most likely due to top-down target selection within a larger object.
Description: The Supplementary Material for this article can be found
online at: http://journal.frontiersin.org/article/10.3389/fnhum.2015.005662016-12-08T10:31:51ZIn-situ detection of microbial life in the deep biosphere in igneous ocean crusthttp://hdl.handle.net/2381/38865
Title: In-situ detection of microbial life in the deep biosphere in igneous ocean crust
Authors: Salas, E. C.; Bhartia, R.; Anderson, Louise; Hug, W. F.; Reid, R. D.; Iturrino, G.; Edwards, K. J.
Abstract: The deep biosphere is a major frontier to science. Recent studies have shown the presence and activity of cells in deep marine sediments and in the continental deep biosphere. Volcanic lavas in the deep ocean subsurface, through which substantial fluid flow occurs, present another potentially massive deep biosphere. We present results from the deployment of a novel in-situ logging tool designed to detect microbial life harbored in a deep, native, borehole environment within igneous oceanic crust, using deep ultraviolet native fluorescence spectroscopy. Results demonstrate the predominance of microbial-like signatures within the borehole environment, with densities in the range of 105 cells/mL. Based on transport and flux models, we estimate that such a concentration of microbial cells could not be supported by transport through the crust, suggesting in situ growth of these communities.
Description: The Supplementary Material for this article can be found online at: http://journal.frontiersin.org/article/10.3389/fmicb.2015.012602016-12-08T10:26:18ZHuman bioturbation, and the subterranean landscape of the Anthropocenehttp://hdl.handle.net/2381/38864
Title: Human bioturbation, and the subterranean landscape of the Anthropocene
Authors: Zalasiewicz, Jan; Waters, C. N.; Williams, Mark
Abstract: Bioturbation by humans ('anthroturbation'), comprising phenomena ranging from surface landscaping to boreholes that penetrate deep into the crust, is a phenomenon without precedent in Earth history, being orders of magnitude greater in scale than any preceding non-human type of bioturbation. These human phenomena range from simple individual structures to complex networks that range to several kilometres depth (compared with animal burrows that range from centimetres to a few metres in depth), while the extraction of material from underground can lead to topographic subsidence or collapse, with concomitant modification of the landscape. Geological transformations include selective removal of solid matter (e.g. solid hydrocarbons, metal ores), fluids (natural gas, liquid hydrocarbons, water), local replacement by other substances (solid waste, drilling mud), associated geochemical and mineralogical changes to redox conditions with perturbation of the water table and pH conditions and local shock-metamorphic envelopes with melt cores (in the case of underground nuclear tests). These transformations started in early/mid Holocene times, with the beginning of mining for flint and metals, but show notable inflections associated with the Industrial Revolution (ca 1800 CE) and with the 'Great Acceleration' at ∼1950 CE, the latter date being associated with the large-scale extension of this phenomenon from sub-land surface to sub-sea floor settings. Geometrically, these phenomena cross-cut earlier stratigraphy. Geologically, they can be regarded as a subsurface expression of the surface chronostratigraphic record of the Anthropocene. These subsurface phenomena have very considerable potential for long-term preservation.2016-12-08T10:17:14ZTravelling with the Traveller: an ethnographic framework for the study of digital inclusion and immigration.http://hdl.handle.net/2381/38863
Title: Travelling with the Traveller: an ethnographic framework for the study of digital inclusion and immigration.
Authors: Tsatsou, P.; Boursinou, N.
Abstract: This paper argues that researchers who study immigrants’ digital inclusion need to shed light
on immigrants’ use of digital technologies within the time frame and context of the
‘immigration travel’ and while immigrants are in transition to a new or safer place for
resettlement. In support of this argument, the paper proposes a ‘travelling with the traveller’
research framework that applies the ethnographic methodology and aims at the researcher
experiencing or even becoming an integral part of the immigration travel. The paper presents
the proposed travelling with the traveller framework and discusses how it can offer genuine
insights into the implications of digital inclusion (or the absence of it) for immigrants
experiencing, combating or alleviating all sorts of adversities, volatile emotions, unanticipated
problems and moments of uncertainty crisis they so often encounter while on the move from
homeland to another land, from one life setting to another. Further, the paper presents the
fieldwork processes and data collection techniques of the proposed travelling with the traveller
framework, such as participant observation, informal and open-ended interviews, as well as the
use of video and photographic footage.2016-12-08T09:48:16ZEvaluation of biomass burning across North West Europe and its impact on air qualityhttp://hdl.handle.net/2381/38862
Title: Evaluation of biomass burning across North West Europe and its impact on air quality
Authors: Cordell, R. L.; Mazet, M.; Dechoux, C.; Hama, S. M. L.; Staelens, J.; Hofman, J.; Stroobants, C.; Roekens, E.; Kos, G. P. A.; Weijers, E. P.; Frumau, K. F. A.; Panteliadis, P.; Delaunay, T.; Wyche, K. P.; Monks, P. S.
Abstract: Atmospheric particulate pollution is a significant problem across the EU and there is concern that there may be an increasing contribution from biomass burning, driven by rising fuel prices and an increased interest in the use of renewable energy sources. This study was carried out to assess current levels of biomass burning and the contribution to total PM10 across five sites in North-West Europe; an area which is frequently affected by poor air quality. Biomass burning was quantified by the determination of levoglucosan concentrations from PM10 aerosol filters collected over a 14 month period in 2013/2014 and continued for a further 12 months at the UK site in Leicester. Levoglucosan levels indicated a distinct period of increased biomass combustion between November and March. Within this period monthly average concentrations ranged between 23 ± 9.7 and 283 ± 163 ng/m3, with Lille showing consistently higher levels than the sites in Belgium, the Netherlands and the UK. The estimated contribution to PM10 was, as expected, highest in the winter season where the season average percentage contribution was lowest in Wijk aan Zee at 2.7 ± 1.4% and again highest in Lille at 11.6 ± 3.8%, with a PM10 mass concentration from biomass that ranged from 0.56 μg/m3 in Leicester to 2.08 μg/m3 in Lille. Overall there was poor correlation between the levoglucosan concentrations measured at the different sites indicating that normally biomass burning would only affect atmospheric particulate pollution in the local area; however, there was evidence that extreme burning events such as the Easter fires traditionally held in parts of North-West Europe can have far wider ranging effects on air quality. Network validation measurements were also taken using a mobile monitoring station which visited the fixed sites to carry out concurrent collections of aerosol filters; the result of which demonstrated the reliability of both PM10 and levoglucosan measurements.
Description: Supplementary data related to this article can be found at http://dx.doi.org/10.1016/j.atmosenv.2016.06.065.2016-12-07T16:46:29ZReflections on the discovery space for a large ultraviolet-visible telescope: Inputs from the European-led EUVO exercisehttp://hdl.handle.net/2381/38861
Title: Reflections on the discovery space for a large ultraviolet-visible telescope: Inputs from the European-led EUVO exercise
Authors: Gómez De Castro, A. I.; Gaensicke, B.; Neiner, C.; Barstow, Martin A.
Abstract: The solutions to a number of astrophysical problems require access to the ultraviolet, optical, and infrared from space-based facilities, with capabilities beyond those available with Hubble Space Telescope or James Webb Space Telescope. A large ultraviolet-optical-infrared telescope will need to have a large collecting area and milliarcsecond angular resolution capabilities plus highly efficient instruments, providing a revolutionary enhancement in capability. During 2013, the European astronomical community was involved in an exercise to outline the big science that could be achieved with such a facility; the proposal was called EUVO (as per European Ultraviolet-Visible Observatory). Inspired by that work, we describe a proposal on future science and instrumentation to be carried out with a 10-m class telescope.2016-12-07T16:34:28ZLinking permeability to crack density evolution in thermally stressed rocks under cyclic loadinghttp://hdl.handle.net/2381/38860
Title: Linking permeability to crack density evolution in thermally stressed rocks under cyclic loading
Authors: Faoro, I.; Vinciguerra, S.; Marone, C.; Elsworth, D.; Schubnel, A.
Abstract: To improve our understanding of the complex coupling between circulating fluids and the development of crack damage, we performed flow-through tests on samples of Etna basalt and Westerly granite that were cyclically loaded by deviatoric stresses. The basalt was naturally microfractured, while the relatively crack-free Westerly granite was thermally pretreated to 500°C and 800°C to generate microcrack damage. Samples were repeatedly loaded and then unloaded under deviatoric stress paths and ultimately to failure. Permeability and water volume content were measured throughout the loading history together with the differential stress. Permeability decreases at low differential stresses and increases at intermediate differential stresses up to a steady value at failure. We use water volume content as a proxy for fluid storage and show that both permeability and storage evolve with damage and evolution of crack density. We use crack models to represent the evolution of permeability as a function of loading state and are able to independently link it to the observed evolution of deformability, used as an independent measure of crack density.
Description: Additional supporting information may be found in the online version of
this article.2016-12-07T16:25:28ZColorimetric biomimetic sensor systems based on molecularly imprinted polymer membranes for highly-selective detection of phenol in environmental sampleshttp://hdl.handle.net/2381/38859
Title: Colorimetric biomimetic sensor systems based on molecularly imprinted polymer membranes for highly-selective detection of phenol in environmental samples
Authors: Sergeyeva, T. A.,; Chelyadina, D. S.; Gorbach, L. A.; Brovko, O. O.; Piletska, E. V.; Piletsky, S. A.; Sergeeva, L. M.; El’skaya, A. V.
Abstract: Aim. Development of an easy-to-use colorimetric sensor system for fast and accurate detection of phenol in envi- ronmental samples. Methods. Technique of molecular imprinting, method of in situ polymerization of molecularly imprinted polymer membranes. Results. The proposed sensor is based on free-standing molecularly imprinted polymer (MIP) membranes, synthesized by in situ polymerization, and having in their structure artificial binding sites capable of selective phenol recognition. The quantitative detection of phenol, selectively adsorbed by the MIP membranes, is based on its reaction with 4-aminoantipyrine, which gives a pink-colored product. The intensity of staining of the MIP membrane is proportional to phenol concentration in the analyzed sample. Phenol can be detected within the range 50 nM–10 mM with limit of detection 50 nM, which corresponds to the concentrations that have to be detected in natural and waste waters in accordance with environmental protection standards. Stability of the MIP-membrane-based sensors was assessed during 12 months storage at room temperature. Conclusions. The sensor system provides highly-selective and sensitive detection of phenol in both mo- del and real (drinking, natural, and waste) water samples. As compared to traditional methods of phenol detection, the proposed system is characterized by simplicity of operation and can be used in non-laboratory conditions.2016-12-07T16:00:42ZThe status and future of EUV astronomyhttp://hdl.handle.net/2381/38858
Title: The status and future of EUV astronomy
Authors: Barstow, M. A.; Casewell, S. L.; Holberg, J. B.; Kowalski, M. P.
Abstract: The Extreme Ultraviolet wavelength range was one of the final windows to be opened up to astronomy. Nevertheless, it provides very important diagnostic tools for a range of astronomical objects, although the opacity of the interstellar medium restricts the majority of observations to sources in our own galaxy. This review gives a historical overview of EUV astronomy, describes current instrumental capabilities and examines the prospects for future facilities on small and medium-class satellite platforms.2016-12-07T15:47:18ZBrown Dwarf Companions to White Dwarfshttp://hdl.handle.net/2381/38857
Title: Brown Dwarf Companions to White Dwarfs
Authors: Burleigh, Matt R.; Steele, P. R.; Dobbie, P. D.; Farihi, Jay; Napiwotzki, R.; Maxted, P. F. L.; Barstow, Martin A.; Jameson, Richard F.; Casewell, Sarah L.; Gaensicke, B. T.; Marsh, T. R.
Editors: Schuh, S; Drechsel, H; Heber, U
Abstract: Brown dwarf companions to white dwarfs are rare, but recent infra-red surveys are
slowly revealing examples. We present new observations of the post-common envelope binary
WD0137−349, which reveals the effects of irradiation on the ≈ 0.05M⊙ secondary, and new observations
of GD 1400 which show that it too is a close, post-common envelope system. We also
present the latest results in a near-infrared photometric search for unresolved ultra-cool companions
and to white dwarfs with UKIDSS. Twenty five DA white dwarfs were identified as having photometric
excesses indicative of a low mass companion, with 8-10 of these having a predicted mass in
the range associated with brown dwarfs. The results of this survey show that the unresolved (< 2”)
brown dwarf companion fraction to DA white dwarfs is 0.3 ≤ fWD+BD ≤ 1.3%
Description: PACS: 97,982016-12-07T15:42:38ZThe Joint astrophysical plasmadynamic EXperiment (J-PEX): A high-resolution rocket spectrometerhttp://hdl.handle.net/2381/38856
Title: The Joint astrophysical plasmadynamic EXperiment (J-PEX): A high-resolution rocket spectrometer
Authors: Barstow, Martin A.; Bannister, Nigel P.; Cruddace, R. G.; Kowalski, M. P.; Wood, K. S.; Yentis, D. J.; Gursky, H.; Barbee, T. W.; Goldstein, W. H.; Kordas, J. F.; Fritz, G. G.; Culhane, J. L.; Lapington, J. S.
Editors: Blades, J. C.; Siegmund, O. H. W.
Abstract: We report on the successful sounding rocket flight of the high resolution (R=3000-4000) J-PEX EUV spectrometer. J-PEX is a novel normal incidence instrument, which combines the focusing and dispersive elements of the spectrometer into a single optical element, a multilayer-coated grating. The high spectral resolution achieved has had to be matched by unprecedented high spatial resolution in the imaging microchannel plate detector used to record the data. We illustrate the performance of the complete instrument through an analysis of the 220-245Å spectrum of the white dwarf G191-B2B obtained with a 300 second exposure. The high resolution allows us to detect a low-density ionized helium component along the line of sight to the star and individual absorption lines from heavier elements in the photosphere.2016-12-07T15:35:36ZHeavy Element Abundance Patterns in Hot White Dwarfs from a Survey of the FUSE Archivehttp://hdl.handle.net/2381/38855
Title: Heavy Element Abundance Patterns in Hot White Dwarfs from a Survey of the FUSE Archive
Authors: Barstow, M. A.; Casewell, S. L.; Holberg, J. B.; Barstow, J. K.
Editors: Krzesinski, J.; Stachowski, G.; Moskalik, P.; Bajan, K.
Abstract: We present a series of systematic abundance measurements for 89 hot
DA white dwarfs drawn from the FUSE observation archive. These stars span the temperature
range ≈ 20000-70000K, and form the largest sample to-date, exceeding our
earlier study, based mainly on IUE and HST data, by a factor three. Using the heavy
element blanketed non-LTE stellar atmosphere calculations from this previous work,
we are able to measure the abundances of carbon, silicon, phosphorus and sulphur and
examine how they change as the stars cool. We are able to establish the broad range
of abundances seen in a given temperature range and establish the incidence of stars
which, like HZ43, appear to (surprisingly) be completely devoid of any material other
than H in their atmospheres. As a result we can begin to identify stars with peculiar
abundances in this temperature range and determine whether or not these objects might
be accreting planetary debris, as has been inferred for many cooler objects.2016-12-07T15:28:39Ztheta Hya: spectroscopic identification of a second B star plus white dwarf binaryhttp://hdl.handle.net/2381/38854
Title: theta Hya: spectroscopic identification of a second B star plus white dwarf binary
Authors: Burleigh, MR; Barstow, MA
Abstract: We report the identification, in an Extreme Ultraviolet
Explorer (EUVE) spectrum, of a hot white dwarf companion
to the 3rd magnitude late-B star θ Hya (HR3665, HD79469).
This is the second B star+white dwarf binary to be conclusively
identified; Vennes et al. (1997), and Burleigh & Barstow
(1998) had previously reported the spectroscopic discovery of
a hot white dwarf companion to the B5V star y Pup (HR2875).
Since these two degenerate stars must have evolved from main
sequence progenitors more massive than their B star companions,
they can be used to place observational lower limits on
the maximum mass for white dwarf progenitors, and to investigate
the upper end of the initial-final mass relation. Assuming
a pure hydrogen composition, we constrain the temperature of
the white dwarf companion to θ Hya to lie between 25,000K
and 31,000K. We also predict that a third bright B star, 16 Dra
(B9.5V), might also be hiding an unresolved hot white dwarf
companion.2016-12-07T12:13:24ZH.E.S.S. Limits on Linelike Dark Matter Signatures in the 100 GeV to 2 TeV Energy Range Close to the Galactic Center.http://hdl.handle.net/2381/38853
Title: H.E.S.S. Limits on Linelike Dark Matter Signatures in the 100 GeV to 2 TeV Energy Range Close to the Galactic Center.
Authors: Abdalla, H.; Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Akhperjanian, A. G.; Andersson, T.; Angüner, E. O.; Arrieta, M.; Aubert, P.; Backes, M.; Balzer, A.; Barnard, M.; Becherini, Y.; Becker Tjus, J.; Berge, D.; Bernhard, S.; Bernlöhr, K.; Birsin, E.; Blackwell, R.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Bregeon, J.; Brun, F.; Brun, P.; Bryan, M.; Bulik, T.; Capasso, M.; Carr, J.; Casanova, S.; Chakraborty, N.; Chalme-Calvet, R.; Chaves, R. C.; Chen, A.; Chevalier, J.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Condon, B.; Conrad, J.; Couturier, C.; Cui, Y.; Davids, I. D.; Degrange, B.; Deil, C.; Devin, J.; deWilt, P.; Djannati-Ataï, A.; Domainko, W.; Donath, A.; Drury, L. O.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Ernenwein, J. P.; Eschbach, S.; Farnier, C.; Fegan, S.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Förster, A.; Funk, S.; Füßling, M.; Gabici, S.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Gottschall, D.; Goyal, A.; Grondin, M. H.; Grudzińska, M.; Hadasch, D.; Hahn, J.; Hawkes, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hoischen, C.; Holler, M.; Horns, D.; Ivascenko, A.; Jacholkowska, A.; Jamrozy, M.; Janiak, M.; Jankowsky, D.; Jankowsky, F.; Jingo, M.; Jogler, T.; Jouvin, L.; Jung-Richardt, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kerszberg, D.; Khélifi, B.; Kieffer, M.; King, J.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kolitzus, D.; Komin, N.; Kosack, K.; Krakau, S.; Kraus, M.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lau, J.; Lees, J. P.; Lefaucheur, J.; Lefranc, V.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J. P.; Leser, E.; Liu, R.; Lohse, T.; Lorentz, M.; Lypova, I.; Marandon, V.; Marcowith, A.; Mariaud, C.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; Meintjes, P. J.; Meyer, M.; Mitchell, A. M.; Moderski, R.; Mohamed, M.; Morå, K.; Moulin, E.; Murach, T.; de Naurois, M.; Niederwanger, F.; Niemiec, J.; Oakes, L.; O'Brien, P.; Odaka, H.; Ohm, S.; Ostrowski, M.; Öttl, S.; Oya, I.; Padovani, M.; Panter, M.; Parsons, R. D.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Perennes, C.; Petrucci, P. O.; Peyaud, B.; Pita, S.; Poon, H.; Prokhorov, D.; Prokoph, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Reimer, A.; Reimer, O.; Renaud, M.; de Los Reyes, R.; Rieger, F.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Salek, D.; Sanchez, D. A.; Santangelo, A.; Sasaki, M.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwemmer, S.; Settimo, M.; Seyffert, A. S.; Shafi, N.; Shilon, I.; Simoni, R.; Sol, H.; Spanier, F.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Tavernet, J. P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tibaldo, L.; Tluczykont, M.; Trichard, C.; Tuffs, R.; van der Walt, J.; van Eldik, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Voisin, F.; Völk, H. J.; Vuillaume, T.; Wadiasingh, Z.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Yang, R.; Zabalza, V.; Zaborov, D.; Zacharias, M.; Zdziarski, A. A.; Zech, A.; Zefi, F.; Ziegler, A.; Żywucka, N.; H.E.S.S. Collaboration
Abstract: A search for dark matter linelike signals iss performed in the vicinity of the Galactic Center by the H.E.S.S. experiment on observational data taken in 2014. An unbinned likelihood analysis iss developed to improve the sensitivity to linelike signals. The upgraded analysis along with newer data extend the energy coverage of the previous measurement down to 100 GeV. The 18 h of data collected with the H.E.S.S. array allow one to rule out at 95% C.L. the presence of a 130 GeV line (at l=-1.5°, b=0° and for a dark matter profile centered at this location) previously reported in Fermi-LAT data. This new analysis overlaps significantly in energy with previous Fermi-LAT and H.E.S.S. RESULTS: No significant excess associated with dark matter annihilations was found in the energy range of 100 GeV to 2 TeV and upper limits on the gamma-ray flux and the velocity weighted annihilation cross section are derived adopting an Einasto dark matter halo profile. Expected limits for present and future large statistics H.E.S.S. observations are also given.2016-12-07T12:06:02ZNonlinear association of BMI with all-cause and cardiovascular mortality in type 2 diabetes mellitus: a systematic review and meta-analysis of 414,587 participants in prospective studieshttp://hdl.handle.net/2381/38852
Title: Nonlinear association of BMI with all-cause and cardiovascular mortality in type 2 diabetes mellitus: a systematic review and meta-analysis of 414,587 participants in prospective studies
Authors: Zaccardi, Francesco; Dhalwani, NN; Papamargaritis, Dimitris; Webb, David R.; Murphy, Gavin J.; Davies, Melanie J.; Khunti, Kamlesh
Abstract: Aims/hypothesis: The relationship between BMI and mortality has been extensively investigated in the general population; however, it is less clear in people with type 2 diabetes. We aimed to assess the association of BMI with all-cause and cardiovascular mortality in individuals with type 2 diabetes mellitus. Methods: We searched electronic databases up to 1 March 2016 for prospective studies reporting associations for three or more BMI groups with all-cause and cardiovascular mortality in individuals with type 2 diabetes mellitus. Study-specific associations between BMI and the most-adjusted RR were estimated using restricted cubic splines and a generalised least squares method before pooling study estimates with a multivariate random-effects meta-analysis. Results: We included 21 studies including 24 cohorts, 414,587 participants, 61,889 all-cause and 4470 cardiovascular incident deaths; follow-up ranged from 2.7 to 15.9 years. There was a strong nonlinear relationship between BMI and all-cause mortality in both men and women, with the lowest estimated risk from 31–35 kg/m2 and 28–31 kg/m2 (p value for nonlinearity <0.001) respectively. The risk of mortality at higher BMI values increased significantly only in women, whilst lower values were associated with higher mortality in both sexes. Limited data for cardiovascular mortality were available, with a possible inverse linear association with BMI (higher risk for BMI <27 kg/m2). Conclusions/interpretation: In type 2 diabetes, BMI is nonlinearly associated with all-cause mortality with lowest risk in the overweight group in both men and women. Further research is needed to clarify the relationship with cardiovascular mortality and assess causality and sex differences.
Description: The online version of this article (doi:10.1007/s00125-016-4162-6) contains peer-reviewed but unedited supplementary material, which is available to authorised users. Statistical codes and datasets are available from the corresponding author.2016-12-07T11:54:50ZRevered and Elevated or Invisible and Condemned, a male concern: Perspectives of Male Primary Teachers in English Primary Schoolshttp://hdl.handle.net/2381/38851
Title: Revered and Elevated or Invisible and Condemned, a male concern: Perspectives of Male Primary Teachers in English Primary Schools
Authors: Ryan, John Vincent
Abstract: This research critiques and explores how male primary school teachers construct their professional identities. The research also focuses on masculinity and femininity in public discourse and outlines how particular professions attract significantly higher or fewer males or females. In parallel, the study critiques the concepts of teacher professionalism and gendered behaviour linked to gendered assumptions underlying dominant conceptions of the professional male primary teacher.
This research investigates the construction of male primary school teacher’s identities and its gendered dimensions. The significance of positioning strategies adopted by male practitioners in primary schools is explored. Contributory factors to professional identities, which are partly formulated by colleagues, parents, children and policy- makers is researched. Responses to policy assumptions and rhetoric are also shared. This research is also widened to examine the 'moral panic' (Cohen, 1972) apparent when discussing a lack of male primary school teachers in English schools and how many assumptions are articulated regarding the advocacy of a more balanced gendered profession in primary education.
Findings reveal that the professional identities of male primary school teachers in this study are shaped by many influences, including policy. Following an analysis of the findings the significance of male teachers as role models; stereotypical behaviour and masculinity in primary schools; safeguarding; child protection and social spaces and the juxtaposition of power were revealed.2016-12-07T11:47:48ZSpectroscopic confirmation of a white dwarf companion to the B star 16 Drahttp://hdl.handle.net/2381/38850
Title: Spectroscopic confirmation of a white dwarf companion to the B star 16 Dra
Authors: Burleigh, MR; Barstow, MA
Abstract: Using an Extreme Ultraviolet Explorer (EUVE)
spectrum, we confirm the identification of a white dwarf companion
to the B9.5V star 16 Dra (HD150100), and constrain its
surface temperature to lie between 29,000 K and 35,000 K. This
is the third B star + white dwarf non-interacting Sirius-type binary
to be confirmed, after y Pup (HR2875, HD59635) and θ
Hya (HR3665, HD79469). 16 Dra and its white dwarf companion
are members of a larger resolved proper motion system
including the B9V star 17 Dra A (HD150117). The white dwarf
must have evolved from a progenitor more massive than this
star, MMS ≈ 3.7M . White dwarf companions to B stars are
important since they set an observational limit on the maximum
mass for white dwarf progenitors, and can potentially be used to
investigate the high mass ends of the initial-final mass relation
and the white dwarf mass-radius relation.2016-12-07T10:33:46ZFinding the UV-Visible Path Forward: Proceedings of the Community Workshop to Plan the Future of UV/Visible Space Astrophysicshttp://hdl.handle.net/2381/38849
Title: Finding the UV-Visible Path Forward: Proceedings of the Community Workshop to Plan the Future of UV/Visible Space Astrophysics
Authors: Scowen, P. A.; Tripp, T.; Beasley, M.; Ardila, D.; Andersson, B-G.; Apellániz, J. M.; Barstow, Martin; Bianchi, L.; Calzetti, D.; Clampin, M.; Evans, C. J.; France, K.; García, M. G.; Castro, A. G. D.; Harris, W.; Hartigan, P.; Howk, J. C.; Hutchings, J.; Larruquert, J.; Lillie, C. F.; Matthews, G.; McCandliss, S.; Polidan, R.; Perez, M. R.; Rafelski, M.; Roederer, I. U.; Sana, H.; Sanders, W. T.; Schiminovich, D.; Thronson, H.; Tumlinson, J.; Vallerga, J.; Wofford, A.
Abstract: We present the science cases and technological discussions that came from the workshop entitled "Finding the UV-Visible Path Forward" held at NASA GSFC June 25-26, 2015. The material presented outlines the compelling science that can be enabled by a next generation space-based observatory dedicated for UV-visible science, the technologies that are available to include in that observatory design, and the range of possible alternative launch approaches that could also enable some of the science. The recommendations to the Cosmic Origins Program Analysis Group from the workshop attendees on possible future development directions are outlined.
Description: Proceedings from Workshop held in June 2015 at NASA GSFC on the Future of UV Astronomy from Space2016-12-07T10:16:51ZHourglass stabilization and the virtual element methodhttp://hdl.handle.net/2381/38848
Title: Hourglass stabilization and the virtual element method
Authors: Cangiani, A.; Manzini, G.; Russo, A.; Sukumar, N.
Abstract: In this paper, we establish the connections between the virtual element method (VEM) and the hourglass control techniques that have been developed since the early 1980s to stabilize underintegrated C0 Lagrange finite element methods. In the VEM, the bilinear form is decomposed into two parts: a consistent term that reproduces a given polynomial space and a correction term that provides stability. The essential ingredients of inline image-continuous VEMs on polygonal and polyhedral meshes are described, which reveals that the variational approach adopted in the VEM affords a generalized and robust means to stabilize underintegrated finite elements. We focus on the heat conduction (Poisson) equation and present a virtual element approach for the isoparametric four-node quadrilateral and eight-node hexahedral elements. In addition, we show quantitative comparisons of the consistency and stabilization matrices in the VEM with those in the hourglass control method of Belytschko and coworkers. Numerical examples in two and three dimensions are presented for different stabilization parameters, which reveals that the method satisfies the patch test and delivers optimal rates of convergence in the L2 norm and the H1 seminorm for Poisson problems on quadrilateral, hexahedral, and arbitrary polygonal meshes.2016-12-06T15:38:40ZOn the stability of continuous-discontinuous Galerkin methods for advection-diffusion-reaction problemshttp://hdl.handle.net/2381/38847
Title: On the stability of continuous-discontinuous Galerkin methods for advection-diffusion-reaction problems
Authors: Cangiani, Andrea; Chapman, J.; Georgoulis, Emmanuil; Jensen, M.
Abstract: We consider a finite element method which couples the continuous Galerkin method away from internal and boundary layers with a discontinuous Galerkin method in the vicinity of layers. We prove that this consistent method is stable in the streamline diffusion norm if the convection field flows non-characteristically from the region of the continuous Galerkin to the region of the discontinuous Galerkin method. The stability properties of the coupled method are illustrated with a numerical experiment.2016-12-06T15:29:49ZThe interaction of He(-) with fullerenes.http://hdl.handle.net/2381/38846
Title: The interaction of He(-) with fullerenes.
Authors: Mauracher, A.; Daxner, M.; Huber, S. E.; Postler, J.; Renzler, M.; Denifl, S.; Scheier, P.; Ellis, Andrew M.
Abstract: The effects of interactions between He(-) and clusters of fullerenes in helium nanodroplets are described. Electron transfer from He(-) to (C60)n and (C70)n clusters results in the formation of the corresponding fullerene cluster dianions. This unusual double electron transfer appears to be concerted and is most likely guided by electron correlation between the two very weakly bound outer electrons in He(-). We suggest a mechanism which involves long range electron transfer followed by the conversion of He(+)into He2 (+), where formation of the He-He bond in He2 (+) releases sufficient kinetic energy for the cation and the dianion to escape their Coulombic attraction. By analogy with the corresponding dications, the observation of a threshold size of n ≥ 5 for formation of both (C60)n (2-) and (C70)n (2-) is attributed to Coulomb explosion rather than an energetic constraint. We also find that smaller dianions can be observed if water is added as a co-dopant. Other aspects of He(-) chemistry that are explored include its role in the formation of multiply charged fullerene cluster cations and the sensitivity of cluster dianion formation on the incident electron energy.2016-12-06T15:20:26ZSubmersion of potassium clusters in helium nanodropletshttp://hdl.handle.net/2381/38845
Title: Submersion of potassium clusters in helium nanodroplets
Authors: Lan, L. A. D.; Bartl, P.; Leidlmair, C.; Schoebel, H.; Denifl, S.; Maerk, T. D.; Ellis, Andrew M.; Scheier, P.
Abstract: Small alkali clusters do not submerge in liquid helium nanodroplets but instead survive predominantly in high spin states that reside on the surface of the nanodroplet. However, a recent theoretical prediction by Stark and Kresin [Phys. Rev. B 81, 085401 (2010)], based on a classical description of the energetics of bubble formation for a fully submerged alkali cluster, suggests that the alkali clusters can submerge on energetic grounds when they exceed a critical size. Following recent work on sodium clusters, where ion yield data from electron impact mass spectrometry was used to obtain the first experimental evidence for alkali cluster submersion, we report here on similar experiments for potassium clusters. Evidence is presented for full cluster submersion at n>80 for Kn clusters, which is in good agreement with the recent theoretical prediction. In an additional observation, we report “magic number” sizes for both Kn+ and Kn2+ ions derived from helium droplets, which are found to be consistent with the jellium model.
Description: PACS number(s): 68.08.Bc, 36.40.−c2016-12-06T15:12:45ZThe dance goes on forever? Art schools, class and UK higher educationhttp://hdl.handle.net/2381/38844
Title: The dance goes on forever? Art schools, class and UK higher education
Authors: Banks, Mark; Oakley, K.
Abstract: For most of the twentieth century, the UK ‘art school’ was widely seen as an accessible alternative to University. In Art into Pop, Simon Frith and Howard Horne revealed how this state-funded art and design training, linked to manufacturing industries and backed by relatively low or informal entry requirements, offered the prospect of social and economic uplift for hitherto marginalised working-class youth. More recently, however, while enrolments have expanded, art schools have become absorbed into conventional universities and the class profile, at least at the more prestigious colleges, has changed significantly. Simultaneously, art schools, together with other forms of higher education (HE) have been yoked to a broader public policy agenda of the ‘creative economy’ – one that often marginalises working-class people. This paper takes the changing nature of the art school as its starting point for discussion of class, HE and the creative economy workforce.2016-12-06T15:08:28ZComparing the protests of undocumented migrants beyond contexts: collective actions as acts of emancipationhttp://hdl.handle.net/2381/38843
Title: Comparing the protests of undocumented migrants beyond contexts: collective actions as acts of emancipation
Authors: Monforte, Pierre; Dufour, P.
Abstract: In this article, we demonstrate that the collective actions of undocumented migrants possess similar symbolic dimensions, even if the contexts of their actions differ. We explain this finding by focusing on the power relations that undocumented migrants face. Given that they occupy a very specific position in society (i.e., they are neither included in nor completely excluded from citizenship), they experience similar forms of power relations vis-à-vis public authorities in different countries. We argue that this leads them to participate in collective actions as acts of emancipation. Our analysis illustrates this argument by comparing marches by undocumented migrants in three countries: France, Germany and Canada-Quebec. Through an in-depth analysis, we demonstrate that these marches redefine the legal order and politicize the presence of undocumented migrants in the public sphere. By highlighting the cognitive, emotional and relational dimensions of collective actions, we show that the symbolic dimension of these three marches relates to the empowerment, pride and solidarity of undocumented migrants.2016-12-06T15:02:34Z